Deposition of sensing layers for surface acoustic wave chemical sensors based on supra-molecular chemistry

Abstract

The design and deposition of a sensing layer for room temperature SAW/BAW chemical sensors utilizing macrocyclic compounds in accordance with supra-molecular chemistry principles. The gas to be sensed is attached to the organic sensing film thus changing its visco-elastic properties and creating a mass increase of the film deposited on the surface of SAW/BAW devices. A direct printing method can be used as an additive, mask-less procedure to deposit metallic interdigital transducers and electrodes required for SAW/BAW devices, along with the deposition of a guiding layer and the organic films only on the location required by the sensing SAW/BAW principle of the sensor. Different thermal treatment solutions can be used for the consolidation of the gelly organic films deposited by the direct printing methods.

What is claimed is: 
     
       1. A method for the design and deposition of organic sensing layers for surface acoustic wave chemical sensors, comprising:
 designing and synthesizing an organic sensing film based on a plurality of chemical routes, wherein one chemical route is selected from said plurality of chemical routes using a dynamic molecular recognition principle; 
 synthesizing said organic sensing film based on at least one polymeric calixarenes non-covalently bonded to said piezoelectric substrate; 
 preparing a homogeneous liquid phase of said at least one polymeric calixarenes by means of a polymerization or copolymerization of a monomer with at least one α,ω-dithiol wherein said monomer comprises 25,26,27,28-tetra10-undecenoxy calix[4]arene obtained by reacting p-tertbutylcalix[4]arene with a 10-undecenoyl chloride; 
 depositing said designed and synthesized organic sensing film over a dielectric wave guiding layer on a plurality of electrodes pre-formed on a piezoelectric substrate forming a gelly organic sensing film; and 
 consolidating said gelly organic sensing film utilizing at least one thermal treatment solution comprising a local laser treatment applied to avoid cracking said gelly organic sensing film, to form said organic sensing film, thereby forming a gas sensor for the detection of a plurality of gases utilizing a change in mass load and visco-elastic properties of said organic sensing film. 
 
     
     
       2. The method of  claim 1  wherein depositing said organic sensing film over said dielectric wave guiding layer on a plurality of electrodes pre-formed on a piezoelectric substrate further comprises:
 depositing, utilizing a maskless direct printing operation, said organic sensing film and said guiding layer on said plurality of electrodes pre-formed on said piezoelectric substrate. 
 
     
     
       3. The method of  claim 1  wherein depositing said organic sensing film over said dielectric wave guiding layer on a plurality of electrodes pre-formed on a piezoelectric substrate further comprises:
 depositing, utilizing at least one classical deposition operation, said organic sensing film and said wave guiding layer on said plurality of electrodes pre-formed on said piezoelectric substrate. 
 
     
     
       4. The method of  claim 1  wherein said at least one α,ω-dithiol is 1,3-dithiolpropane. 
     
     
       5. The method of  claim 1  wherein a plurality of target molecules to be detected by said at least one polymeric calixarene comprises an aromatic hydrocarbon and a volatile organic compound. 
     
     
       6. A method for the design and deposition of organic sensing layers for surface acoustic wave chemical sensors, comprising:
 designing and synthesizing an organic sensing film based on a plurality of chemical routes; 
 synthesizing said organic sensing film based on at least one polymeric calixarenes non-covalently bonded to said piezoelectric substrate; 
 preparing a homogeneous liquid phase of said at least one polymeric calixarenes by means of a polymerization or copolymerization of a monomer with at least one α,ω-dithiol wherein said monomer comprises 25,26,27,28-tetra10-undecenoxy calix[4]arene obtained by reacting p-tertbutylcalix[4]arene with a 10-undecenoyl chloride; 
 depositing, utilizing a maskless direct printing operation, said organic sensing film and a dielectric wave guiding layer on a plurality of electrodes pre-formed on said piezoelectric substrate; 
 consolidating said organic sensing film utilizing at least one thermal treatment solution, thereby forming a gas sensor for the detection of a plurality of gases utilizing a change in mass load and visco-elastic properties of said organic sensing film.